Materials for electronic devices

ABSTRACT

The present application relates to spirobifluorene derivatives of a formula (I), to the use thereof in electronic devices, especially in organic electroluminescent devices (OLEDs), where they may be used in hole-transporting function, and to processes for preparing said derivatives. The compounds have one or more properties selected from very good hole-conducting properties, very good electron-blocking properties, high glass transition temperature, high oxidation stability, good solubility and high thermal stability.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a national stage application (under 35 U.S.C. § 371)of PCT/EP2015/002475, filed Dec. 8, 2015, which claims benefit ofEuropean Application No. 14004355.5, filed Dec. 22, 2014, both of whichare incorporated herein by reference in their entirety.

The present application relates to a spirobifluorene derivative of aformula (I) defined hereinafter which is suitable for use in electronicdevices, especially organic electroluminescent devices (OLEDs).

BACKGROUND OF THE INVENTION

Electronic devices in the context of this application are understood tomean what are called organic electronic devices, which contain organicsemiconductor materials as functional materials. More particularly,these are understood to mean OLEDs.

The structure of OLEDs in which organic compounds are used as functionalmaterials is described, for example, in U.S. Pat. No. 4,539,507, U.S.Pat. No. 5,151,629, EP 0676461 and WO 98/27136. In general, the termOLEDs is understood to mean electronic devices which have one or morelayers comprising organic compounds and emit light on application ofelectrical voltage.

In electronic devices, especially OLEDs, there is great interest inimproving the performance data, especially lifetime, efficiency andoperating voltage. In these aspects, it has not yet been possible tofind any entirely satisfactory solution.

A great influence on the performance data of electronic devices ispossessed by layers having a hole-transporting function, for examplehole-injecting layers, hole transport layers, electron blocker layersand also emitting layers. For use in these layers, there is a continuoussearch for new materials having hole-transporting properties.

It is known in the prior art that triarylamines can be used in theselayers as materials having hole-transporting properties. Thetriarylamines may be monotriarylamines as described, for example, in JP1995/053955, WO 2006/123667 and JP 2010/222268, or bis- or otheroligoamines, as described, for example, in U.S. Pat. No. 7,504,163 or US2005/0184657. Known examples of triarylamine compounds as materialshaving hole-transporting properties for OLEDs includetris-p-biphenylamine,N,N′-di-1-naphthyl-N,N′-diphenyl-1,1′-biphenyl-4,4′-diamine (NPB) and4,4′,4″-tris(3-methylphenylphenylamino)triphenylamine (MTDATA).

Additionally known in the prior art is the use ofspirobifluorene-arylamino compounds in OLEDs, including as holetransport materials (WO 2012/034627 and WO 2013/120577).

BRIEF SUMMARY OF THE INVENTION

In the course of studies relating to novel materials for use in OLEDs,it has now been found that, surprisingly, compounds having an arylamineor carbazole group and having a spirobifluorene unit fused onto abenzothiophene unit are of outstanding suitability for use in OLEDs,especially as materials having hole-transporting function.

The compounds found have one or more properties selected from very goodhole-conducting properties, very good electron-blocking properties, highglass transition temperature, high oxidation stability, good solubilityand high thermal stability. When the compounds found are used in OLEDs,especially in hole-transporting function, very good device performancedata, especially very good lifetime and quantum efficiency of thedevices, are observed.

DETAILED DESCRIPTION OF THE INVENTION

The present invention therefore provides a compound of the formula (I)

-   -   which has a group of the formula (T)

bonded at two adjacent positions marked by * to the base structure offormula (I), where the condensation is such that any bond marked by * informula (T) is attached at a position marked by * to the base structureof formula (I)

-   -   which may be substituted at one or more positions shown as        unsubstituted in the base structure of formula (I) and the group        of the formula (T) by an R¹ radical; and    -   which has the following definitions of the variables:    -   A is the same or different at each instance and is a group of        the formula (A1), (A2) or (A3) which is bonded via the bond        marked with # and may be substituted at one or more positions        shown as unsubstituted by an R² radical;

-   -   Ar¹ is the same or different at each instance and is a single        bond or an aromatic or heteroaromatic ring system which has 6 to        30 aromatic ring atoms and may be substituted by one or more R²        radicals;    -   Ar² is the same or different at each instance and is an aromatic        or heteroaromatic ring system which has 6 to 30 aromatic ring        atoms and may be substituted by one or more R² radicals;    -   X is the same or different at each instance and is a single bond        or a group selected from BR², C(R²)₂, Si(R²)₂, C═O, O, S, S═O,        SO₂, NR², PR² and P(═O)R²;    -   Y is selected from O, S and Se;    -   Z is selected from O, S, Se and a single bond, where Z is not a        single bond when Y is O;    -   R⁰ is the same or different at each instance and is selected        from H, D, F, CN, Si(R³)₃, straight-chain alkyl or alkoxy groups        having 1 to 20 carbon atoms, branched or cyclic alkyl or alkoxy        groups having 3 to 20 carbon atoms, alkenyl or alkynyl groups        having 2 to 20 carbon atoms, aromatic ring systems having 6 to        40 aromatic ring atoms, and heteroaromatic ring systems having 5        to 40 aromatic ring atoms; where the alkyl, alkoxy, alkenyl and        alkynyl groups mentioned and the aromatic ring systems and        heteroaromatic ring systems mentioned may each be substituted by        one or more R³ radicals; and where one or more CH₂ groups in the        alkyl, alkoxy, alkenyl and alkynyl groups mentioned may be        replaced by —R³C═CR³—, —C≡C—, Si(R³)₂, C═O, C═NR³, —C(═O)O—,        —C(═O)NR³—, NR³, P(═O)(R³), —O—, —S—, SO or SO₂;    -   R¹ is the same or different at each instance and is selected        from H, D, F, C(═O)R³, CN, Si(R³)₃, P(═O)(R³)₂, OR³, S(═O)R³,        S(═O)₂R³, straight-chain alkyl or alkoxy groups having 1 to 20        carbon atoms, branched or cyclic alkyl or alkoxy groups having 3        to 20 carbon atoms, alkenyl or alkynyl groups having 2 to 20        carbon atoms, aromatic ring systems having 6 to 40 aromatic ring        atoms, and heteroaromatic ring systems having 5 to 40 aromatic        ring atoms; where two or more R¹ radicals may be joined to one        another and may form a ring; where the alkyl, alkoxy, alkenyl        and alkynyl groups mentioned and the aromatic ring systems and        heteroaromatic ring systems mentioned may each be substituted by        one or more R³ radicals; and where one or more CH₂ groups in the        alkyl, alkoxy, alkenyl and alkynyl groups mentioned may be        replaced by —R³C═CR³—, —C≡C—, Si(R³)₂, C═O, C═NR³, —C(═O)O—,        —C(═O)NR³—, NR³, P(═O)(R³), —O—, —S—, SO or SO₂;    -   R² is the same or different at each instance and is selected        from H, D, F, C(═O)R³, CN, Si(R³)₃, N(R³)₂, P(═O)(R³)₂, OR³,        S(═O)R³, S(═O)₂R³, straight-chain alkyl or alkoxy groups having        1 to 20 carbon atoms, branched or cyclic alkyl or alkoxy groups        having 3 to 20 carbon atoms, alkenyl or alkynyl groups having 2        to 20 carbon atoms, aromatic ring systems having 6 to 40        aromatic ring atoms, and heteroaromatic ring systems having 5 to        40 aromatic ring atoms; where two or more R² radicals may be        joined to one another and may form a ring; where the alkyl,        alkoxy, alkenyl and alkynyl groups mentioned and the aromatic        ring systems and heteroaromatic ring systems mentioned may each        be substituted by one or more R³ radicals; and where one or more        CH₂ groups in the alkyl, alkoxy, alkenyl and alkynyl groups        mentioned may be replaced by —R³C═CR³—, —C≡C—, Si(R³)₂, C═O,        C═NR³, —C(═O)O—, —C(═O)NR³—, NR³, P(═O)(R³), —O—, —S—, SO or        SO₂;    -   R³ is the same or different at each instance and is selected        from H, D, F, C(═O)R⁴, CN, Si(R⁴)₃, N(R⁴)₂, P(═O)(R⁴)₂, OR⁴,        S(═O)R⁴, S(═O)₂R⁴, straight-chain alkyl or alkoxy groups having        1 to 20 carbon atoms, branched or cyclic alkyl or alkoxy groups        having 3 to 20 carbon atoms, alkenyl or alkynyl groups having 2        to 20 carbon atoms, aromatic ring systems having 6 to 40        aromatic ring atoms, and heteroaromatic ring systems having 5 to        40 aromatic ring atoms; where two or more R¹ or R² radicals may        be joined to one another and may form a ring; where the alkyl,        alkoxy, alkenyl and alkynyl groups mentioned and the aromatic        ring systems and heteroaromatic ring systems mentioned may each        be substituted by one or more R⁴ radicals; and where one or more        CH₂ groups in the alkyl, alkoxy, alkenyl and alkynyl groups        mentioned may be replaced by —R⁴C═CR⁴—, —C≡C—, Si(R⁴)₂, C═O,        C═NR⁴, —C(═O)O—, —C(═O)NR⁴—, NR⁴, P(═O)(R⁴), —O—, —S—, SO or        SO₂;    -   R⁴ is the same or different at each instance and is selected        from H, D, F, CN, alkyl groups having 1 to 20 carbon atoms,        aromatic ring systems having 6 to 40 aromatic ring atoms and        heteroaromatic ring systems having 5 to 40 aromatic ring atoms;        where two or more R⁴ radicals may be joined to one another and        may form a ring; and where the alkyl groups, aromatic ring        systems and heteroaromatic ring systems mentioned may be        substituted by F or CN;    -   q is the same or different at each instance and is 0 or 1, where        at least one q in formula (A2) is 1;        i, k, m, n and p are the same or different at each instance and        are 0 or 1, where at least one of these indices is 1.

The groups in square brackets with the indices i, k, m, n and p maygenerally, and in the structures which follow as well, be bonded to thespirobifluorene base skeleton only in those positions shown asunsubstituted. More particularly, they cannot be bonded in positionsthat bear an R⁰ radical.

An aryl group in the context of this invention contains 6 to 40 aromaticring atoms of which none is a heteroatom. An aryl group in the contextof this invention is understood to mean either a simple aromatic cycle,i.e. benzene, or a fused aromatic polycycle, for example naphthalene,phenanthrene or anthracene. A fused aromatic polycycle in the context ofthe present application consists of two or more simple aromatic cyclesfused to one another. Fusion between cycles is understood here to meanthat the cycles share at least one edge with one another.

A heteroaryl group in the context of this invention contains 5 to 40aromatic ring atoms of which at least one is a heteroatom. Theheteroatoms of the heteroaryl group are preferably selected from N, Oand S. A heteroaryl group in the context of this invention is understoodto mean either a simple heteroaromatic cycle, for example pyridine,pyrimidine or thiophene, or a fused heteroaromatic polycycle, forexample quinoline or carbazole. A fused heteroaromatic polycycle in thecontext of the present application consists of two or more simpleheteroaromatic cycles fused to one another. Fusion between cycles isunderstood here to mean that the cycles share at least one edge with oneanother.

An aryl or heteroaryl group, each of which may be substituted by theabovementioned radicals and which may be joined to the aromatic orheteroaromatic system via any desired positions, is especiallyunderstood to mean groups derived from benzene, naphthalene, anthracene,phenanthrene, pyrene, dihydropyrene, chrysene, perylene, triphenylene,fluoranthene, benzanthracene, benzophenanthrene, tetracene, pentacene,benzopyrene, furan, benzofuran, isobenzofuran, dibenzofuran, thiophene,benzothiophene, isobenzothiophene, dibenzothiophene, pyrrole, indole,isoindole, carbazole, pyridine, quinoline, isoquinoline, acridine,phenanthridine, benzo-5,6-quinoline, benzo-6,7-quinoline,benzo-7,8-quinoline, phenothiazine, phenoxazine, pyrazole, indazole,imidazole, benzimidazole, naphthimidazole, phenanthrimidazole,pyridimidazole, pyrazinimidazole, quinoxalinimidazole, oxazole,benzoxazole, naphthoxazole, anthroxazole, phenanthroxazole, isoxazole,1,2-thiazole, 1,3-thiazole, benzothiazole, pyridazine, benzopyridazine,pyrimidine, benzopyrimidine, quinoxaline, pyrazine, phenazine,naphthyridine, azacarbazole, benzocarboline, phenanthroline,1,2,3-triazole, 1,2,4-triazole, benzotriazole, 1,2,3-oxadiazole,1,2,4-oxadiazole, 1,2,5-oxadiazole, 1,3,4-oxadiazole, 1,2,3-thiadiazole,1,2,4-thiadiazole, 1,2,5-thiadiazole, 1,3,4-thiadiazole, 1,3,5-triazine,1,2,4-triazine, 1,2,3-triazine, tetrazole, 1,2,4,5-tetrazine,1,2,3,4-tetrazine, 1,2,3,5-tetrazine, purine, pteridine, indolizine andbenzothiadiazole.

An aromatic ring system in the context of this invention contains 6 to40 carbon atoms in the ring system and does not include any heteroatomsas aromatic ring atoms. An aromatic ring system in the context of thisinvention therefore does not contain any heteroaryl groups. An aromaticring system in the context of this invention shall be understood to meana system which does not necessarily contain only aryl groups but inwhich it is also possible for a plurality of aryl groups to be bonded bya single bond or by a non-aromatic unit, for example one or moreoptionally substituted C, Si, N, O or S atoms. In this case, thenonaromatic unit comprises preferably less than 10% of the atoms otherthan H, based on the total number of atoms other than H in the system.For example, systems such as 9,9′-spirobifluorene, 9,9′-diarylfluorene,triarylamine, diaryl ethers and stilbene are also to be regarded asaromatic ring systems in the context of this invention, and likewisesystems in which two or more aryl groups are joined, for example, by alinear or cyclic alkyl, alkenyl or alkynyl group or by a silyl group. Inaddition, systems in which two or more aryl groups are joined to oneanother via single bonds are also to be regarded as aromatic ringsystems in the context of this invention, for example systems such asbiphenyl and terphenyl.

A heteroaromatic ring system in the context of this invention contains 5to 40 aromatic ring atoms, at least one of which is a heteroatom. Theheteroatoms of the heteroaromatic ring system are preferably selectedfrom N, O and/or S. A heteroaromatic ring system corresponds to theabovementioned definition of an aromatic ring system, but has at leastone heteroatom as one of the aromatic ring atoms. In this way, itdiffers from an aromatic ring system in the sense of the definition ofthe present application, which, according to this definition, cannotcontain any heteroatom as aromatic ring atom.

An aromatic ring system having 6 to 40 aromatic ring atoms or aheteroaromatic ring system having 5 to 40 aromatic ring atoms isespecially understood to mean groups derived from the groups mentionedabove under aryl groups and heteroaryl groups, and from biphenyl,terphenyl, quaterphenyl, fluorene, spirobifluorene, dihydrophenanthrene,dihydropyrene, tetrahydropyrene, indenofluorene, truxene, isotruxene,spirotruxene, spiroisotruxene, indenocarbazole, or from combinations ofthese groups.

In the context of the present invention, a straight-chain alkyl grouphaving 1 to 20 carbon atoms and a branched or cyclic alkyl group having3 to 20 carbon atoms and an alkenyl or alkynyl group having 2 to 40carbon atoms in which individual hydrogen atoms or CH₂ groups may alsobe replaced by the groups mentioned above in the definition of theradicals are preferably understood to mean the methyl, ethyl, n-propyl,i-propyl, n-butyl, i-butyl, s-butyl, t-butyl, 2-methylbutyl, n-pentyl,s-pentyl, cyclopentyl, neopentyl, n-hexyl, cyclohexyl, neohexyl,n-heptyl, cycloheptyl, n-octyl, cyclooctyl, 2-ethyihexyl,trifluoromethyl, pentafluoroethyl, 2,2,2-trifluoroethyl, ethenyl,propenyl, butenyl, pentenyl, cyclopentenyl, hexenyl, cyclohexenyl,heptenyl, cycloheptenyl, octenyl, cyclooctenyl, ethynyl, propynyl,butynyl, pentynyl, hexynyl or octynyl radicals.

An alkoxy or thioalkyl group having 1 to 20 carbon atoms in whichindividual hydrogen atoms or CH₂ groups may also be replaced by thegroups mentioned above in the definition of the radicals is preferablyunderstood to mean methoxy, trifluoromethoxy, ethoxy, n-propoxy,i-propoxy, n-butoxy, i-butoxy, s-butoxy, t-butoxy, n-pentoxy, s-pentoxy,2-methylbutoxy, n-hexoxy, cyclohexyloxy, n-heptoxy, cycloheptyloxy,n-octyloxy, cyclooctyloxy, 2-ethylhexyloxy, pentafluoroethoxy,2,2,2-trifluoroethoxy, methylthio, ethylthio, n-propylthio,i-propylthio, n-butylthio, i-butyithio, s-butylthio, t-butylthio,n-pentylthio, s-pentylthio, n-hexylthio, cyclohexylthio, n-heptylthio,cycloheptylthio, n-octylthio, cyclooctylthio, 2-ethylhexylthio,trifluoromethylthio, pentafluoroethylthio, 2,2,2-trifluoroethylthio,ethenylthio, propenylthio, butenylthio, pentenylthio, cyclopentenylthio,hexenylthio, cyclohexenylthio, heptenylthio, cycloheptenylthio,octenylthio, cyclooctenylthio, ethynylthio, propynylthio, butynylthio,pentynylthio, hexynylthio, heptynylthio or octynylthio.

The wording that two or more radicals together may form a ring, in thecontext of the present application, shall be understood to mean, interalia, that the two radicals are joined to one another by a chemicalbond. In addition, however, the abovementioned wording shall also beunderstood to mean that, if one of the two radicals is hydrogen, thesecond radical binds to the position to which the hydrogen atom wasbonded, forming a ring.

It is preferable that A is a group of the formula (A-1) or (A-3), morepreferably a group of the formula (A-1).

It is preferable that Ar¹ is the same or different at each instance andis selected from a single bond and a divalent group derived frombenzene, biphenyl, terphenyl, fluorene, spirobifluorene, indenofluorene,carbazole, dibenzofuran or dibenzothiophene, each optionally substitutedby R² radicals, or a combination of two or more of these groups, but notmore than 30 aromatic ring atoms may be present in Ar¹.

Ar¹ groups are preferably selected from groups of the followingformulae:

where the dotted bonds represent the bonds to the radical of the formulaand the groups may be substituted at the free positions by one or moreR² radicals, but are preferably unsubstituted at the free positions.

R² in the groups of the formulae (Ar¹-23) and (Ar¹-24) is preferably thesame or different and is an alkyl group having 1 to 10 carbon atoms,especially methyl, or is a phenyl group which may be substituted by oneor more R³ radicals and is preferably unsubstituted. Two alkyl groups R²may also form a ring with formation of a spiro group, preferably acyclohexyl ring or a cyclopentyl ring.

It is preferable that Ar² is the same or different at each instance andis selected from an aromatic or heteroaromatic ring system which has 6to 25 aromatic ring atoms and may be substituted by one or more R²radicals. Particular preference is given to phenyl, biphenyl, terphenyl,fluorenyl, spirobifluorenyl, indenofluorenyl, naphthyl, phenanthrenyl,furanyl, benzofuranyl, dibenzofuranyl, thiophenyl, benzothiophenyl,dibenzothiophenyl, carbazolyl, indolocarbazolyl and indenocarbazolyl,each of which may be substituted by one or more R² radicals.

Ar² groups are preferably the same or different at each instance and areselected from groups of the following formulae:

where the dotted bond represents the bond to the nitrogen and the groupsmay be substituted at the free positions by one or more R² radicals, butare preferably unsubstituted at the free positions.

R² in the groups of the formulae (Ar²-68) to (Ar²-82), (Ar²-85) to(Ar²-87), (Ar²-129) and (Ar²-130) is preferably the same or differentand is an alkyl group having 1 to 10 carbon atoms, especially methyl, ora phenyl group which may be substituted by one or more R³ radicals andis preferably unsubstituted. Two alkyl groups R² may also form a ringwith formation of a spiro group, preferably a cyclohexyl ring or acyclopentyl ring.

It is preferable that X is the same or different at each instance and isselected from a single bond or a group selected from C(R²)₂, C═O, O, Sand NR²; more preferably, X is a single bond.

R⁰ is preferably the same or different at each instance and is selectedfrom H, D, F, straight-chain alkyl or alkoxy groups having 1 to 10carbon atoms, branched or cyclic alkyl or alkoxy groups having 3 to 10carbon atoms, aromatic ring systems having 6 to 40 aromatic ring atomsand heteroaromatic ring systems having 5 to 40 aromatic ring atoms,where said alkyl and alkoxy groups and said aromatic ring systems andheteroaromatic ring systems may each be substituted by one or more R³radicals. More preferably, R⁰ is the same or different at each instanceand is H, F, a straight-chain alkyl group having 1 to 10 carbon atoms, abranched or cyclic alkyl group having 3 to 10 carbon atoms, an aromaticring system having 6 to 30 aromatic ring atoms or a heteroaromatic ringsystem having 5 to 30 aromatic ring atoms, where said alkyl groups andsaid aromatic ring systems and said heteroaromatic ring systems may eachbe substituted by one or more R³ radicals. Most preferably, R⁰ is H.

Preferably, R¹ and R² are the same or different at each instance and areH, D, F, CN, Si(R³)₃, a straight-chain alkyl or alkoxy group having 1 to10 carbon atoms, a branched or cyclic alkyl or alkoxy group having 3 to10 carbon atoms or an aromatic or heteroaromatic ring system having 6 to30 aromatic ring atoms, where two or more R¹ or R² radicals may bejoined to one another and may form a ring, where said alkyl and alkoxygroups and said aromatic and heteroaromatic ring systems may each besubstituted by one or more R³ radicals, and where one or more CH₂ groupsin the alkyl and alkoxy groups mentioned may be replaced by —C≡C—,—R³C═CR³—, Si(R³)₂, C═O, C═NR³, —NR³—, —O—, —S—, —C(═O)O— or —C(═O)NR³—.

More preferably, R¹ and R² are the same or different at each instanceand are H, D, F, CN, a straight-chain alkyl group having 1 to 10 carbonatoms or a branched or cyclic alkyl group having 3 to 10 carbon atoms,or an aromatic or heteroaromatic ring system having 6 to 25 aromaticring atoms, where said alkyl and alkoxy groups and said aromatic orheteroaromatic ring systems may each be substituted by one or more R³radicals. Most preferably, R¹ and R² are the same or different at eachinstance and are H, F, CN, methyl, tert-butyl, phenyl, biphenyl,dibenzofuran, dibenzothiophene or carbazole.

Preferably, R³ is the same or different at each instance and is H, D, F,CN, Si(R⁴)₃, N(R⁴)₂, a straight-chain alkyl or alkoxy group having 1 to10 carbon atoms or a branched or cyclic alkyl or alkoxy group having 3to 10 carbon atoms or an aromatic or heteroaromatic ring system having 5to 30 aromatic ring atoms, where two or more R³ radicals may be joinedto one another and may form a ring, where said alkyl and alkoxy groupsand said aromatic or heteroaromatic ring systems may each be substitutedby one or more R⁴ radicals, and where one or more CH₂ groups in thealkyl and alkoxy groups mentioned may be replaced by —C≡C—, —R⁴C═CR⁴—,Si(R⁴)₂, C═O, C═NR⁴, —NR⁴—, —O—, —S—, —C(═O)O— or —C(═O)NR⁴—. Morepreferably, R³ is the same or different at each instance and is H, D, F,CN, N(R⁴)₂, a straight-chain alkyl group having 1 to 10 carbon atoms ora branched or cyclic alkyl group having 3 to 10 carbon atoms, or anaromatic or heteroaromatic ring system having 6 to 25 aromatic ringatoms, where said alkyl and alkoxy groups and said aromatic orheteroaromatic ring systems may each be substituted by one or more R⁴radicals.

It is preferable that p is 1. In this case, it is further preferablethat all the other indices k, i, m and n are 0.

It is preferable that k is 1. In this case, it is further preferablethat all the other indices i, m, n and p are 0.

It is further preferable that the sum of the indices i, k, m, n and p is1 or 2, more preferably 1.

Preferably, the Y group is S, and the Z group is O, S or a single bond.More preferably, the Y group is S, and the Z group is a single bond.

Preferred embodiments of the compounds of the formula (I) correspond tothe following formulae:

where the symbols that occur are as defined above, and the compounds maybe substituted at positions shown as unsubstituted by R¹ radicals.

Particular preference among the formulae specified is given to theformulae (I-1) to (I-12).

For formulae (I-1) to (I-24), in particular, the preferred embodimentsof R⁰, Ar¹ and A apply. Preferably, for formulae (I-1) to (I-24), the Ygroup is S, and the Z group is O, S or a single bond; more preferably,the Y group is S, and the Z group is a single bond. It is additionallyespecially preferable for the abovementioned formulae that R⁰ is H.

Most preferred among the formulae (I-1), (I-3), (I-5), (I-7), (I-9) and(I-11) are the following formulae:

where the symbols that occur are as defined above, and the compounds maybe substituted at positions shown as unsubstituted by R¹ radicals.

For the formulae just mentioned, in particular, the preferredembodiments of R⁰, Ar¹ and A apply. Preferably, the Y group is S, andthe Z group is O, S or a single bond; more preferably, the Y group is S,and the Z group is a single that R⁰ is H.

The following explicit compounds are preferred embodiments of thecompounds of the formula (I):

The synthesis of the compounds of formula (I) can be conducted usingprocesses and reaction types known in the prior art, for examplehalogenation, organometallic addition, Buchwald coupling and Suzukicoupling.

Schemes 1 to 8 show possible synthesis routes for preparation of theinventive compounds. They serve to elucidate the invention to the personskilled in the art, and should not be interpreted in a restrictivemanner. The person skilled in the art will be able, within the scope ofhis common knowledge in the art, to modify the synthesis routes shown,or to develop other routes if this appears to be more advantageous.

In all the synthesis schemes that follow, the compounds are shown inunsubstituted form. This does not rule out the presence of any desiredsubstituents in the processes.

Scheme 1 shows a suitable synthesis for the intermediate of formula(Z-1).

Scheme 2 shows a suitable synthesis for the intermediate of formula(Z-2).

Scheme 3 shows a suitable synthesis for intermediates of formulae (Z-3)and (Z-4).

Scheme 4 shows a suitable alternative synthesis for intermediates offormulae (Z-5) and (Z-6).

The synthesis units shown above may be provided with a reactive group,for example bromine, on the benzothiophene unit, as shown by thefollowing scheme (formula (Z-7)):

The intermediates of the formulae (Z-1) to (Z-7) provided with reactivegroups, as shown above, are versatile synthesis units which can beconverted to compounds of the formula (I) as shown by the followingscheme:

The process shown in Scheme 6, via the functionalization with boronicacid (middle), is especially suitable for preparing compounds in which adiarylamine or a carbazole is bonded to the spirobifluorene unit via anarylene or heteroarylene spacer.

According to an alternative process for preparing the inventivecompounds (Scheme 7), the procedure is analogous to Schemes 1 to 4,except that a diarylamino group is present in place of the reactive RGgroup in the fluorenone derivative. Scheme 7 merely shows the reactionanalogous to Scheme 1. However, it is also possible in the same way tomodify the processes according to Schemes 2 to 4, in each case byexchange of the RG group for a corresponding diarylamino group.

According to a modification of the processes shown in Schemes 1 to 4 and7, it is also possible to use analogous compounds, for examplethianthrene derivatives, rather than dibenzothiophene derivatives in thesynthesis of the base skeleton. This is shown by way of example inScheme 8. Again, modifications are possible, in a corresponding mannerto Schemes 2 to 5.

The compounds of the formula (Z-6) obtained can, as shown in Scheme 6,be converted further to the final compounds of formula (I). It is alsopossible to use the thianthrene derivatives to conduct modifications tothe synthesis according to Scheme 7.

The present application thus provides a process for preparing a compoundof the formula (I), characterized in that either

A) first the spirobifluorene base skeleton substituted by a reactivegroup is prepared by reacting a dibenzothiophenyl derivative with afluorenone derivative bearing the reactive group and, in a later step,via an organometallic coupling reaction, a diarylamino or carbazolegroup or an aryl or heteroaryl group substituted by a diarylamino orcarbazole group is introduced at the position of the reactive group, orB) the reaction of a dibenzothiophenyl derivative with a fluorenonebearing a diarylamino or carbazole group or an aryl or heteroaryl groupsubstituted by a diarylamino or carbazole group is involved, orC) first a spirobifluorene base skeleton is prepared by reacting adibenzothiophenyl derivative with a fluorenone derivative, then thelatter is functionalized with a reactive group and, in a later step, viaan organometallic coupling reaction, a diarylamino or carbazole group oran aryl or heteroaryl group substituted by a diarylamino or carbazolegroup is introduced at the position of the reactive group.

The reactive group is preferably a halogen atom, more preferably Br. Theorganometallic coupling reaction is preferably a Buchwald coupling or aSuzuki coupling.

The above-described compounds, especially compounds substituted byreactive leaving groups, such as bromine, iodine, chlorine, boronic acidor boronic ester, may find use as monomers for production ofcorresponding oligomers, dendrimers or polymers. Suitable reactiveleaving groups are, for example, bromine, iodine, chlorine, boronicacids, boronic esters, amines, alkenyl or alkynyl groups having aterminal C—C double bond or C—C triple bond, oxiranes, oxetanes, groupswhich enter into a cycloaddition, for example a 1,3-dipolarcycloaddition, for example dienes or azides, carboxylic acidderivatives, alcohols and silanes.

The invention therefore further provides oligomers, polymers ordendrimers containing one or more compounds of formula (I), wherein thebond(s) to the polymer, oligomer or dendrimer may be localized at anydesired positions substituted by R⁰, R¹ or R² in formula (I). Accordingto the linkage of the compound of formula (I), the compound is part of aside chain of the oligomer or polymer or part of the main chain. Anoligomer in the context of the invention is understood to mean acompound formed from at least three monomer units. A polymer in thecontext of the invention is understood to mean a compound formed from atleast ten monomer units. The inventive polymers, oligomers or dendrimersmay be conjugated, partly conjugated or nonconjugated. The inventiveoligomers or polymers may be linear, branched or dendritic. In thestructures having linear linkage, the units of formula (I) may be joineddirectly to one another, or they may be joined to one another via abivalent group, for example via a substituted or unsubstituted alkylenegroup, via a heteroatom or via a bivalent aromatic or heteroaromaticgroup. In branched and dendritic structures, it is possible, forexample, for three or more units of formula (1) to be joined by atrivalent or higher-valency group, for example via a trivalent orhigher-valency aromatic or heteroaromatic group, to give a branched ordendritic oligomer or polymer.

For the repeat units of formula (I) in oligomers, dendrimers andpolymers, the same preferences apply as described above for compounds offormula (I).

For preparation of the oligomers or polymers, the monomers of theinvention are homopolymerized or copolymerized with further monomers.Suitable and preferred comonomers are chosen from fluorenes (for exampleaccording to EP 842208 or WO 2000/22026), spirobifluorenes (for exampleaccording to EP 707020, EP 894107 or WO 2006/061181), paraphenylenes(for example according to WO 1992/18552), carbazoles (for exampleaccording to WO 2004/070772 or WO 2004/113468), thiophenes (for exampleaccording to EP 1028136), dihydrophenanthrenes (for example according toWO 2005/014689 or WO 2007/006383), cis- and trans-indenofluorenes (forexample according to WO 2004/041901 or WO 2004/113412), ketones (forexample according to WO 2005/040302), phenanthrenes (for exampleaccording to WO 2005/104264 or WO 2007/017066) or else a plurality ofthese units. The polymers, oligomers and dendrimers typically containstill further units, for example emitting (fluorescent orphosphorescent) units, for example vinyltriarylamines (for exampleaccording to WO 2007/068325) or phosphorescent metal complexes (forexample according to WO 2006/003000), and/or charge transport units,especially those based on triarylamines.

The inventive polymers and oligomers are generally prepared bypolymerization of one or more monomer types, of which at least onemonomer leads to repeat units of the formula (I) in the polymer.Suitable polymerization reactions are known to those skilled in the artand are described in the literature. Particularly suitable and preferredpolymerization reactions which lead to formation of C—C or C—N bonds arethe SUZUKI polymerization, the YAMAMOTO polymerization, the STILLEpolymerization and the HARTWIG-BUCHWALD polymerization.

How the polymerization can be conducted by these methods and how thepolymers can then be separated from the reaction medium and purified isknown to those skilled in the art and is described in detail in theliterature, for example in WO 2003/048225, WO 2004/037887 and WO2004/037887.

For the processing of the inventive compounds from the liquid phase, forexample by spin-coating or by printing methods, formulations of theinventive compounds are required. These formulations may, for example,be solutions, dispersions or emulsions. For this purpose, it may bepreferable to use mixtures of two or more solvents. Suitable andpreferred solvents are, for example, toluene, anisole, o-, m- orp-xylene, methyl benzoate, mesitylene, tetralin, veratrole, THF,methyl-THF, THP, chlorobenzene, dioxane, phenoxytoluene, especially3-phenoxytoluene, (−)-fenchone, 1,2,3,5-tetramethylbenzene,1,2,4,5-tetramethylbenzene, 1-methylnaphthalene, 2-methylbenzothiazole,2-phenoxyethanol, 2-pyrrolidinone, 3-methylanisole, 4-methylanisole,3,4-dimethylanisole, 3,5-dimethylanisole, acetophenone, α-terpineol,benzothiazole, butyl benzoate, cumene, cyclohexanol, cyclohexanone,cyclohexylbenzene, decalin, dodecylbenzene, ethyl benzoate, indane,methyl benzoate, NMP, p-cymene, phenetole, 1,4-diisopropylbenzene,dibenzyl ether, diethylene glycol butyl methyl ether, triethylene glycolbutyl methyl ether, diethylene glycol dibutyl ether, triethylene glycoldimethyl ether, diethylene glycol monobutyl ether, tripropylene glycoldimethyl ether, tetraethylene glycol dimethyl ether,2-isopropylnaphthalene, pentylbenzene, hexylbenzene, heptylbenzene,octylbenzene, 1,1-bis(3,4-dimethylphenyl)ethane or mixtures of thesesolvents.

The invention therefore further provides a formulation, especially asolution, dispersion or emulsion, comprising at least one compound offormula (I) or at least one polymer, oligomer or dendrimer containing atleast one unit of formula (I) and at least one solvent, preferably anorganic solvent. The way in which such solutions can be prepared isknown to those skilled in the art and is described, for example, in WO2002/072714, WO 2003/019694 and the literature cited therein.

The inventive compounds are suitable for use in electronic devices,especially in organic electroluminescent devices (OLEDs). Depending onthe substitution, the compounds are used in different functions andlayers.

The invention therefore further provides for the use of the compound offormula (I) in an electronic device. This electronic device ispreferably selected from the group consisting of organic integratedcircuits (OICs), organic field-effect transistors (OFETs), organicthin-film transistors (OTFTs), organic light-emitting transistors(OLETs), organic solar cells (OSCs), organic optical detectors, organicphotoreceptors, organic field-quench devices (OFQDs), organiclight-emitting electrochemical cells (OLECs), organic laser diodes(O-lasers) and more preferably organic electroluminescent devices(OLEDs).

The invention further provides, as already set out above, an electronicdevice comprising at least one compound of formula (I). This electronicdevice is preferably selected from the abovementioned devices.

It is more preferably an organic electroluminescent device (OLED)comprising anode, cathode and at least one emitting layer, characterizedin that at least one organic layer, which may be an emitting layer, ahole transport layer or another layer, comprises at least one compoundof formula (I).

Apart from the cathode, anode and emitting layer, the organicelectroluminescent device may also comprise further layers. These areselected, for example, from in each case one or more hole injectionlayers, hole transport layers, hole blocker layers, electron transportlayers, electron injection layers, electron blocker layers, excitonblocker layers, interlayers, charge generation layers (IDMC 2003,Taiwan; Session 21 OLED (5), T. Matsumoto, T. Nakada, J. Endo, K. Mod,N. Kawamura, A. Yokoi, J. Kido, Multiphoton Organic EL Device HavingCharge Generation Layer) and/or organic or inorganic p/n junctions.

The sequence of the layers of the organic electroluminescent devicecomprising the compound of the formula (I) is preferably as follows:anode-hole injection layer-hole transport layer-optionally further holetransport layer-optionally electron blocker layer-emittinglayer-optionally hole blocker layer-electron transport layer-electroninjection layer-cathode. It is additionally possible for further layersto be present in the OLED.

The inventive organic electroluminescent device may contain two or moreemitting layers. More preferably, these emission layers in this casehave several emission maxima between 380 nm and 750 nm overall, suchthat the overall result is white emission; in other words, variousemitting compounds which may fluoresce or phosphoresce and which emitblue, green, yellow, orange or red light are used in the emittinglayers. Especially preferred are three-layer systems, i.e. systemshaving three emitting layers, where the three layers show blue, greenand orange or red emission (for the basic construction see, for example,WO 2005/011013). The inventive compounds are preferably present in thehole transport layer, hole injection layer or electron blocker layer.

It is preferable in accordance with the invention when the compound offormula (I) is used in an electronic device comprising one or morephosphorescent emitting compounds. In this case, the compound may bepresent in different layers, preferably in a hole transport layer, anelectron blocker layer, a hole injection layer or an emitting layer.

The term “phosphorescent emitting compounds” typically encompassescompounds where the emission of light is effected through aspin-forbidden transition, for example a transition from an excitedtriplet state or a state having a higher spin quantum number, forexample a quintet state.

Suitable phosphorescent emitting compounds (=triplet emitters) areespecially compounds which, when suitably excited, emit light,preferably in the visible region, and also contain at least one atom ofatomic number greater than 20, preferably greater than 38, and less than84, more preferably greater than 56 and less than 80. Preference isgiven to using, as phosphorescent emitting compounds, compoundscontaining copper, molybdenum, tungsten, rhenium, ruthenium, osmium,rhodium, iridium, palladium, platinum, silver, gold or europium,especially compounds containing iridium, platinum or copper. In thecontext of the present invention, all luminescent iridium, platinum orcopper complexes are considered to be phosphorescent emitting compounds.

Examples of the above-described emitting compounds can be found inapplications WO 00/70655, WO 01/41512, WO 02/02714, WO 02/15645, EP1191613, EP 1191612, EP 1191614, WO 05/033244, WO 05/019373 and US2005/0258742. In general, all phosphorescent complexes as used forphosphorescent OLEDs according to the prior art and as known to thoseskilled in the art in the field of organic electroluminescent devicesare suitable. It is also possible for the person skilled in the art,without exercising inventive skill, to use further phosphorescentcomplexes in combination with the compounds of formula (I) in organicelectroluminescent devices. Further examples are listed in a table whichfollows.

It is also possible in accordance with the invention to use the compoundof formula (I) in an electronic device comprising one or morefluorescent emitting compounds.

In a preferred embodiment of the invention, the compounds of formula (I)are used as hole transport material. In that case, the compounds arepreferably present in a hole transport layer, an electron blocker layeror a hole injection layer.

A hole transport layer according to the present application is a layerhaving a hole-transporting function between the anode and emittinglayer.

Hole injection layers and electron blocker layers are understood in thecontext of the present application to be specific embodiments of holetransport layers. A hole injection layer, in the case of a plurality ofhole transport layers between the anode and emitting layer, is a holetransport layer which directly adjoins the anode or is separatedtherefrom only by a single coating of the anode. An electron blockerlayer, in the case of a plurality of hole transport layers between theanode and emitting layer, is that hole transport layer which directlyadjoins the emitting layer on the anode side.

If the compound of formula (I) is used as hole transport material in ahole transport layer, a hole injection layer or an electron blockerlayer, the compound can be used as pure material, i.e. in a proportionof 100%, in the hole transport layer, or it can be used in combinationwith one or more further compounds. In a preferred embodiment, theorganic layer containing the compound of the formula (I) thenadditionally contains one or more p-dopants. p-Dopants used according tothe present invention are preferably those organic electron acceptorcompounds capable of oxidizing one or more of the other compounds in themixture.

Particularly preferred embodiments of p-dopants are the compoundsdisclosed in WO 2011/073149, EP 1968131, EP 2276085, EP 2213662, EP1722602, EP 2045848, DE 102007031220, U.S. Pat. No. 8,044,390, U.S. Pat.No. 8,057,712, WO 2009/003455, WO 2010/094378, WO 2011/120709, US2010/0096600, WO 2012/095143 and DE 102012209523.

Particularly preferred p-dopants are quinodimethane compounds,azaindenofluorenediones, azaphenalenes, azatriphenylenes, I₂, metalhalides, preferably transition metal halides, metal oxides, preferablymetal oxides containing at least one transition metal or a metal of maingroup 3, and transition metal complexes, preferably complexes of Cu, Co,Ni, Pd and Pt with ligands containing at least one oxygen atom asbonding site. Preference is further given to transition metal oxides asdopants, preferably oxides of rhenium, molybdenum and tungsten, morepreferably Re₂O₇, MoO₃, WO₃ and ReO₃.

The p-dopants are preferably in substantially homogeneous distributionin the p-doped layers. This can be achieved, for example, bycoevaporation of the p-dopant and the hole transport material matrix.

Preferred p-dopants are especially the following compounds:

In a further preferred embodiment of the invention, the compound offormula (I) is used as hole transport material in combination with ahexaazatriphenylene derivative as described in US 2007/0092755.Particular preference is given here to using the hexaazatriphenylenederivative in a separate layer.

In a further embodiment of the present invention, the compound of theformula (I) is used in an emitting layer as matrix material incombination with one or more emitting compounds, preferablyphosphorescent emitting compounds.

The proportion of the matrix material in the emitting layer in this caseis between 50.0% and 99.9% by volume, preferably between 80.0% and 99.5%by volume, and more preferably between 92.0% and 99.5% by volume forfluorescent emitting layers and between 85.0% and 97.0% by volume forphosphorescent emitting layers.

Correspondingly, the proportion of the emitting compound is between 0.1%and 50.0% by volume, preferably between 0.5% and 20.0% by volume, andmore preferably between 0.5% and 8.0% by volume for fluorescent emittinglayers and between 3.0% and 15.0% by volume for phosphorescent emittinglayers.

An emitting layer of an organic electroluminescent device may alsocomprise systems comprising a plurality of matrix materials (mixedmatrix systems) and/or a plurality of emitting compounds. In this casetoo, the emitting compounds are generally those compounds having thesmaller proportion in the system and the matrix materials are thosecompounds having the greater proportion in the system. In individualcases, however, the proportion of a single matrix material in the systemmay be less than the proportion of a single emitting compound.

It is preferable that the compounds of formula (I) are used as acomponent of mixed matrix systems. The mixed matrix systems preferablycomprise two or three different matrix materials, more preferably twodifferent matrix materials. Preferably, in this case, one of the twomaterials is a material having hole-transporting properties and theother material is a material having electron-transporting properties.The compound of the formula (I) is preferably the matrix material havinghole-transporting properties. The desired electron-transporting andhole-transporting properties of the mixed matrix components may,however, also be combined mainly or entirely in a single mixed matrixcomponent, in which case the further mixed matrix component(s) fulfil(s)other functions. The two different matrix materials may be present in aratio of 1:50 to 1:1, preferably 1:20 to 1:1, more preferably 1:10 to1:1 and most preferably 1:4 to 1:1. Preference is given to using mixedmatrix systems in phosphorescent organic electroluminescent devices. Onesource of more detailed information about mixed matrix systems is theapplication WO 2010/108579.

The mixed matrix systems may comprise one or more emitting compounds,preferably one or more phosphorescent emitting compounds. In general,mixed matrix systems are preferably used in phosphorescent organicelectroluminescent devices.

Particularly suitable matrix materials which can be used in combinationwith the inventive compounds as matrix components of a mixed matrixsystem are selected from the preferred matrix materials specified belowfor phosphorescent emitting compounds or the preferred matrix materialsfor fluorescent emitting compounds, according to what type of emittingcompound is used in the mixed matrix system.

Preferred phosphorescent emitting compounds for use in mixed matrixsystems are the same as detailed further up as generally preferredphosphorescent emitter materials.

Preferred embodiments of the different functional materials in theelectronic device are listed hereinafter.

Preferred phosphorescent emitting compounds have already been mentionedabove.

Preferred fluorescent emitting compounds are selected from the class ofthe arylamines. An arylamine or an aromatic amine in the context of thisinvention is understood to mean a compound containing three substitutedor unsubstituted aromatic or heteroaromatic ring systems bonded directlyto the nitrogen. Preferably, at least one of these aromatic orheteroaromatic ring systems is a fused ring system, more preferablyhaving at least 14 aromatic ring atoms. Preferred examples of these arearomatic anthraceneamines, aromatic anthracenediamines, aromaticpyreneamines, aromatic pyrenediamines, aromatic chryseneamines oraromatic chrysenediamines. An aromatic anthraceneamine is understood tomean a compound in which a diarylamino group is bonded directly to ananthracene group, preferably in the 9 position. An aromaticanthracenediamine is understood to mean a compound in which twodiarylamino groups are bonded directly to an anthracene group,preferably in the 9,10 positions. Aromatic pyreneamines, pyrenediamines,chryseneamines and chrysenediamines are defined analogously, where thediarylamino groups in the pyrene are bonded preferably in the 1 positionor 1,6 positions. Further preferred emitting compounds areindenofluoreneamines or -diamines, for example according to WO2006/108497 or WO 2006/122630, benzoindenofluoreneamines or -diamines,for example according to WO 2008/006449, and dibenzoindenofluoreneaminesor -diamines, for example according to WO 2007/140847, and theindenofluorene derivatives having fused aryl groups disclosed in WO2010/012328. Likewise preferred are the pyrenearylamines disclosed in WO2012/048780 and in WO 2013/185871. Likewise preferred are thebenzoindenofluoreneamines disclosed in WO 2014/037077, thebenzofluoreneamines disclosed in WO 2014/106522 and the extendedbenzoindenofluorenes disclosed in WO 2014/111269.

Useful matrix materials, preferably for fluorescent emitting compounds,include materials of various substance classes. Preferred matrixmaterials are selected from the classes of the oligoarylenes (e.g.2,2′,7,7′-tetraphenylspirobifluorene according to EP 676461 ordinaphthylanthracene), especially of the oligoarylenes containing fusedaromatic groups, the oligoarylenevinylenes (e.g. DPVBi or spiro-DPVBiaccording to EP 676461), the polypodal metal complexes (for exampleaccording to WO 2004/081017), the hole-conducting compounds (for exampleaccording to WO 2004/058911), the electron-conducting compounds,especially ketones, phosphine oxides, sulphoxides, etc. (for exampleaccording to WO 2005/084081 and WO 2005/084082), the atropisomers (forexample according to WO 2006/048268), the boronic acid derivatives (forexample according to WO 2006/117052) or the benzanthracenes (for exampleaccording to WO 2008/145239). Particularly preferred matrix materialsare selected from the classes of the oligoarylenes comprisingnaphthalene, anthracene, benzanthracene and/or pyrene or atropisomers ofthese compounds, the oligoarylenevinylenes, the ketones, the phosphineoxides and the sulphoxides. Very particularly preferred matrix materialsare selected from the classes of the oligoarylenes comprising,anthracene, benzanthracene, benzophenanthrene and/or pyrene oratropisomers of these compounds. An oligoarylene in the context of thisinvention shall be understood to mean a compound in which at least threearyl or arylene groups are bonded to one another. Preference is furthergiven to the anthracene derivatives disclosed in WO 2006/097208, WO2006/131192, WO 2007/065550, WO 2007/110129, WO 2007/065678, WO2008/145239, WO 2009/100925, WO 2011/054442 and EP 1553154, and thepyrene compounds disclosed in EP 1749809, EP 1905754 and US2012/0187826.

Preferred matrix materials for phosphorescent emitting compounds are, aswell as the compounds of the formula (I), aromatic ketones, aromaticphosphine oxides or aromatic sulphoxides or sulphones, for exampleaccording to WO 2004/013080, WO 2004/093207, WO 2006/005627 or WO2010/006680, triarylamines, carbazole derivatives, e.g. CBP(N,N-biscarbazolylbiphenyl) or the carbazole derivatives disclosed in WO2005/039246, US 2005/0069729, JP 2004/288381, EP 1205527 or WO2008/086851, indolocarbazole derivatives, for example according to WO2007/063754 or WO 2008/056746, indenocarbazole derivatives, for exampleaccording to WO 2010/136109, WO 2011/000455 or WO 2013/041176,azacarbazole derivatives, for example according to EP 1617710, EP1617711, EP 1731584, JP 2005/347160, bipolar matrix materials, forexample according to WO 2007/137725, silanes, for example according toWO 2005/111172, azaboroles or boronic esters, for example according toWO 2006/117052, triazine derivatives, for example according to WO2010/015306, WO 2007/063754 or WO 2008/056746, zinc complexes, forexample according to EP 652273 or WO 2009/062578, diazasilole ortetraazasilole derivatives, for example according to WO 2010/054729,diazaphosphole derivatives, for example according to WO 2010/054730,bridged carbazole derivatives, for example according to US 2009/0136779,WO 2010/050778, WO 2011/042107, WO 2011/088877 or WO 2012/143080,triphenylene derivatives, for example according to WO 2012/048781, orlactams, for example according to WO 2011/116865 or WO 2011/137951.

Suitable charge transport materials as usable in the hole injection orhole transport layer or electron blocker layer or in the electrontransport layer of the electronic device of the invention are, as wellas the compounds of the formula (I), for example, the compoundsdisclosed in Y. Shirota et al., Chem. Rev. 2007, 107(4), 953-1010, orother materials as used in these layers according to the prior art.

Preferably, the inventive OLED comprises two or more differenthole-transporting layers. The compound of the formula (I) may be usedhere in one or more of or in all the hole-transporting layers. Accordingto a preferred embodiment, the compound of the formula (I) is used inexactly one hole-transporting layer, and other compounds, preferablyaromatic amine compounds, are used in the further hole-transportinglayers present.

Materials used for the electron transport layer may be any materials asused according to the prior art as electron transport materials in theelectron transport layer. Especially suitable are aluminium complexes,for example Alq₃, zirconium complexes, for example Zrq₄, lithiumcomplexes, for example Liq, benzimidazole derivatives, triazinederivatives, pyrimidine derivatives, pyridine derivatives, pyrazinederivatives, quinoxaline derivatives, quinoline derivatives, oxadiazolederivatives, aromatic ketones, lactams, boranes, diazaphospholederivatives and phosphine oxide derivatives. Further suitable materialsare derivatives of the abovementioned compounds as disclosed in JP2000/053957, WO 2003/060956, WO 2004/028217, WO 2004/080975 and WO2010/072300.

Preferred cathodes of the electronic device are metals having a low workfunction, metal alloys or multilayer structures composed of variousmetals, for example alkaline earth metals, alkali metals, main groupmetals or lanthanoids (e.g. Ca, Ba, Mg, Al, In, Mg, Yb, Sm, etc.).Additionally suitable are alloys composed of an alkali metal or alkalineearth metal and silver, for example an alloy composed of magnesium andsilver. In the case of multilayer structures, in addition to the metalsmentioned, it is also possible to use further metals having a relativelyhigh work function, for example Ag or Al, in which case combinations ofthe metals such as Ca/Ag, Mg/Ag or Ba/Ag, for example, are generallyused. It may also be preferable to introduce a thin interlayer of amaterial having a high dielectric constant between a metallic cathodeand the organic semiconductor. Examples of useful materials for thispurpose are alkali metal or alkaline earth metal fluorides, but also thecorresponding oxides or carbonates (e.g. LiF, Li₂O, BaF₂, MgO, NaF, CsF,Cs₂CO₃, etc.). It is also possible to use lithium quinolinate (LiQ) forthis purpose. The layer thickness of this layer is preferably between0.5 and 5 nm.

Preferred anodes are materials having a high work function. Preferably,the anode has a work function of greater than 4.5 eV versus vacuum.Firstly, metals having a high redox potential are suitable for thispurpose, for example Ag, Pt or Au. Secondly, metal/metal oxideelectrodes (e.g. Al/Ni/NiO_(x), Al/PtO_(x)) may also be preferred. Forsome applications, at least one of the electrodes has to be transparentor partly transparent in order to enable the irradiation of the organicmaterial (organic solar cell) or the emission of light (OLED, O-LASER).Preferred anode materials here are conductive mixed metal oxides.Particular preference is given to indium tin oxide (ITO) or indium zincoxide (IZO). Preference is further given to conductive doped organicmaterials, especially conductive doped polymers. In addition, the anodemay also consist of two or more layers, for example of an inner layer ofITO and an outer layer of a metal oxide, preferably tungsten oxide,molybdenum oxide or vanadium oxide.

The device is structured appropriately (according to the application),contact-connected and finally sealed, in order to rule out damagingeffects by water and air.

In a preferred embodiment, the electronic device is characterized inthat one or more layers are coated by a sublimation process. In thiscase, the materials are applied by vapour deposition in vacuumsublimation systems at an initial pressure of less than 10⁻⁵ mbar,preferably less than 10⁻⁶ mbar. In this case, however, it is alsopossible that the initial pressure is even lower, for example less than10⁻⁷ mbar.

Preference is likewise given to an electronic device, characterized inthat one or more layers are coated by the OVPD (organic vapour phasedeposition) method or with the aid of a carrier gas sublimation. In thiscase, the materials are applied at a pressure between 10⁻⁵ mbar and 1bar. A special case of this method is the OVJP (organic vapour jetprinting) method, in which the materials are applied directly by anozzle and thus structured (for example M. S. Arnold et al., Appl. Phys.Lett. 2008, 92, 053301).

Preference is additionally given to an electronic device, characterizedin that one or more layers are produced from solution, for example byspin-coating, or by any printing method, for example screen printing,flexographic printing, nozzle printing or offset printing, but morepreferably LITI (light-induced thermal imaging, thermal transferprinting) or inkjet printing. For this purpose, soluble compounds offormula (I) are needed. High solubility can be achieved by suitablesubstitution of the compounds.

It is further preferable that an electronic device of the invention isproduced by applying one or more layers from solution and one or morelayers by a sublimation method.

According to the invention, the electronic devices comprising one ormore compounds of formula (I) can be used in displays, as light sourcesin lighting applications and as light sources in medical and/or cosmeticapplications (e.g. light therapy).

WORKING EXAMPLES A) Synthesis Examples Example 1: Synthesis of Compounds(1-1) to (1-14)

Synthesis of 4-(2-bromophenyl)dibenzothiophene A-1

80 g (351 mmol) of dibenzothiophene-4-boronic acid (CAS: 108847-20-7),83 g (351 mmol) of 1,2-dibromobenzene and 8.2 g (7.02 mmol) of Pd(Ph₃P)₄are suspended in 700 ml of dioxane. Added gradually to this suspensionare 440 ml (877 mmol) of potassium carbonate solution (2 M), and thereaction mixture is heated under reflux for 18 h. After cooling, theorganic phase is removed, filtered through silica gel, washed threetimes with 200 ml of water and then concentrated to dryness. The residueis purified by chromatography on silica gel. Yield: 95 g (280 mmol), 80%of theory, purity by HPLC >97%.

In a manner analogous to the synthesis of compound A-1 described, thefollowing compounds are prepared:

Reactant 1 Reactant 2 Product Yield A-2

73% A-3

61% A-4

78% A-5

83% A-6

75%

Synthesis of Intermediate B-1

56.3 g (166 mmol) of 4-(2-bromophenyl)dibenzothiophene A-1 are initiallycharged in 700 ml of THF at −78° C. At this temperature, 70 ml of BuLi(2.5 M in hexane) are added dropwise. After 1 hour, 45.2 g (174 mmol) offluoren-9-one in 200 ml of THF are added dropwise. The mixture is leftto stir at room temperature overnight, added to ice-water and extractedwith dichloromethane. The combined organic phases are washed with waterand dried over sodium sulphate. The solvent is removed under reducedpressure and the residue, without further purification, is heated with90 ml of HCl and 1 l of AcOH at 75° C. overnight. After cooling, theprecipitated solid is filtered off with suction and washed twice with150 ml of water and three times with 150 ml each time of ethanol, andfinally recrystallized from heptane. Yield: 54 g (107 mmol), 65%; purityabout 98% by ¹H NMR.

In a manner analogous to the synthesis of compound B-1 described, thefollowing compounds are prepared:

Reactant 1 Reactant 2 Product Yield B-2

70% B-3

62% B-4

75% B-5

68% B-6

70% B-7

65% B-8

80% B-9

B-10

64% B-11

71% B-12

70% B-13

56% B-14

72%

Synthesis of Compound (1-1)

14.3 g (39.5 mmol) of biphenyl-4-yl(9,9-dimethyl-9H-fluoren-2-yl)amineand 19.8 g (39.5 mol) of the bromo-spiro derivative B-1 are dissolved in350 ml of toluene. The solution is degassed and saturated with N₂.Thereafter, 1.55 ml (1.55 mmol) of a 1 M tri-tert-butylphosphinesolution and 173 mg (1.44 mmol) of Pd(AcO)₂ are added thereto, and then9.5 g of sodium tert-butoxide (98.7 mmol) are added. The reactionmixture is heated to boiling under a protective atmosphere for 4 h. Themixture is subsequently partitioned between toluene and water, and theorganic phase is washed three times with water and dried over Na₂SO₄ andconcentrated by rotary evaporation. After the crude product has beenfiltered through silica gel with toluene, the remaining residue isrecrystallized from heptane/toluene and finally sublimed under highvacuum. The purity is 99.9% (HPLC). The yield of compound (1-1) is 22 g(73% of theory).

Synthesis of compounds (1-2) to (1-14)

In a manner analogous to the synthesis of compound (1-1) described inExample 1, the following compounds (1-2) to (1-14) are also prepared:

Reactant 1 Reactant 2 Product Yield 1-2

78% 1-3

78% 1-4

83% 1-5

66% 1-6

67% 1-7

79% 1-8

77% 1-9

72% 1-10

68% 1-11

68% 1-12

74% 1-13

67% 1-14

71%

Example 2: Synthesis of Compounds (2-1) to (2-12)

Synthesis of Intermediate C-1

18 g (44 mmol) of the starting compound are dissolved in 200 ml ofacetonitrile, and 7.5 g (42 mmol) of N-bromosuccinimide are added inportions at room temperature. On completion of conversion, water andethyl acetate are added thereto, and the organic phase is removed, driedand concentrated. The crude product is subsequently stirred repeatedlywith hot MeOH. Yield: 16.13 g (75%) of the bromo-spiro derivative C-1.

In an analogous manner, the following brominated compounds are prepared:

Brominating Reactant 1 reagent Product Yield C-2

NBS

68% C-3

1) nBuLi, −78° C. 2) BrCH₂—CH₂Br

50% C-4

1) nBuLi, −78° C. 2) I₂

45% C-5

1) nBuLi, −78° C. 2) BrCH₂—CH₂Br

40% C-6

1) nBuLi, −78° C. 2) BrCH₂—CH₂Br

40% C7

NBS

66% C-8

1) nBuLi, −78° C. 2) BrCH₂—CH₂Br

50% C-9

1) nBuLi, −78° C. 2) BrCH₂—CH₂Br

48% C-10

NBS

61% C-11

NBS

60%

Synthesis of compounds (2-1) to (2-12)

In a manner analogous to the synthesis of compound (1-1) described inExample 1, the following compounds (2-1) to (2-12) are also prepared:

Reactant 1 Reactant 2 Product Yield 2-1

76% 2-2

80% 2-3

71% 2-4

78% 2-5

82% 2-6

77% 2-7

75% 2-8

81% 2-9

83% 2-10

75% 2-11

75% 2-12

79%

Example 3: Synthesis of Compounds 3-1 to 3-11

Spirofluorene-Boronic Ester Derivative (D-1)

25 g (49.9 mmol) of the spirofluorene-bromo derivative, 14 g (55 mmol)of bis(pinacolato)diborane and 14.7 g (150 mmol) of potassium acetateare suspended in 400 ml of DMF. To this suspension is added 1.22 g (1.5mmol) of 1,1-bis(diphenylphosphino)ferrocenedichloropalladium(II)complex with DCM. The reaction mixture is heated under reflux for 16 h.After cooling, the organic phase is removed, washed three times with 400mL of water and then concentrated to dryness. The residue isrecrystallized from toluene (25 g, 92% yield).

In a manner analogous thereto, the following compounds are prepared:

Reactant 1 Product Yield D-2

80% D-3

83% D-4

88% D-5

88% D-6

76%

Biphenyl-2-yl(biphenyl-4-yl)(4-chlorophenyl)amine (E-1)

23.8 g of biphenyl-2-yl(biphenyl-4-yl)amine (74 mmol) and 21.2 g of4-chloroiodobenzene (89 mmol) are dissolved in 500 ml of toluene. Thesolution is degassed and saturated with N₂. Thereafter, 3 ml (3 mmol) ofa 1 M tri-tert-butylphosphine solution and 0.33 g (1.48 mmol) ofpalladium(II) acetate are added thereto, and then 10.7 g of sodiumtert-butoxide (111 mmol) are added.

The reaction mixture is heated to boiling under a protective atmospherefor 12 h. The mixture is subsequently partitioned between toluene andwater, and the organic phase is washed three times with water and driedover Na₂SO₄ and concentrated by rotary evaporation. After the crudeproduct has been filtered through silica gel with toluene, the remainingresidue is recrystallized from heptane/toluene. The yield is 29 g (90%of theory).

In a manner analogous thereto, the following compounds are prepared:

Reactant 1 Reactant 2 Product Yield E-2

78% E-3

80% E-4

81% E-5

92% E-6

85% E-7

75%

Synthesis of Compound (3-1)

19.05 g (35 mmol) of spirofluorene pinacolboronic ester derivative D-1and 19.0 g (35 mmol) of chloro derivative E-1 are suspended in 300 ml ofdioxane and 10.6 g of caesium fluoride (69.4 mmol). 1.3 g (1.73 mmol) ofbis(tricyclohexylphosphine)palladium dichloride are added to thissuspension, and the reaction mixture is heated under reflux for 24 h.After cooling, the organic phase is removed, filtered through silicagel, washed three times with 100 ml of water and then concentrated todryness. After the crude product has been filtered through silica gelwith toluene, the remaining residue is recrystallized fromheptane/toluene and finally sublimed under high vacuum. The purity is99.9%. The yield is 21.3 g (75% of theory).

Synthesis of Compounds (3-2) to (3-11)

In a manner analogous to the synthesis of compound (3-1) described inExample 1, the following compounds (3-2) to (3-11) are also prepared:

Yie- Reactant 1 Reactant 2 Product ld 3-2

78% 3-3

71% 3-4

82% 3-5

89% 3-6

69% 3-7

75% 3-8

72% 3-9

63% 3-10

75% 3-11

77%

Example 4: Synthesis of Compounds 4-1 to 4-9

Synthesis of compounds F-1 to F-5

27 g (85 mmol) of bis(biphenyl)amine and 22.0 g (85 mmol) of1-bromofluorenone are dissolved in 170 ml of toluene. The solution isdegassed and saturated with N₂. Thereafter, 4 ml (1.7 mmol) of a 10%tri-tert-butylphosphine solution and 0.2 g (0.89 mmol) of Pd(AcO)₂ areadded thereto, and then 12.2 g of sodium tert-butoxide (127 mmol) areadded. The reaction mixture is heated to boiling under a protectiveatmosphere for 12 h. The mixture is subsequently partitioned betweentoluene and water, and the organic phase is washed three times withwater and dried over Na₂SO₄ and concentrated by rotary evaporation.After the crude product has been filtered through silica gel withtoluene, the remaining residue is recrystallized from heptane/toluene.The yield of compound F-1 is 34 g (80% of theory).

Reactant 1 Reactant 2 Product Yield F-2

67% F-3

75% F-4

80% F-5

78%

Synthesis of Compounds F-6 to F-8

In a manner analogous to the synthesis of compound (3-1) described inExample 1, the following compounds (F-6) to (F-8) are also prepared:

Reactant 1 Reactant 2 Product Yield F-6

89% F-7

85% F-8

75%

Synthesis of Compounds 4-1 to 4-9

30 g (88 mmol) of 4-(2-bromophenyl)dibenzothiophene are initiallycharged in 300 ml of THF at −78° C. At this temperature, 39 ml of BuLi(2.5 M in hexane) are added dropwise. After 1 hour, 44 g (88 mmol) offluorenone F-1 in 200 ml of THF are added dropwise. The mixture is leftto stir at room temperature overnight, added to ice-water and extractedwith dichloromethane. The combined organic phases are washed with waterand dried over sodium sulphate. The solvent is removed under reducedpressure and the residue, without further purification, is heated underreflux with 100 ml of HCl and 1200 ml of AcOH at 75° C. overnight. Aftercooling, the precipitated solid is filtered off with suction and washedonce with 100 ml of water and three times with 100 ml each time ofethanol, recrystallized from heptane and finally sublimed under highvacuum. Yield: 40 g (53 mmol), 60%; purity: about 99.9% by HPLC.

In an analogous manner, it is possible to prepare the further compounds4-2 to 4-9:

Reactant 1 Reactant 2 Product Yield 4-2

50% 4-3

61% 4-4

48% 4-5

49% 4-6

45% 4-7

60% 4-8

52% 4-9

60%

Example 5: Synthesis of Compounds 5-1 to 5-3

10.5 g (43 mmol) of 3-phenylcarbazole and 18 g (36 mmol) of thebromo-spiro derivative are dissolved in 30 ml of toluene. The solutionis degassed and saturated with N₂. Thereafter, 1.44 ml (1.44 mmol) of a1 M tri-tert-butylphosphine solution and 660 mg (0.72 mmol) of Pd₂(dba)₃are added thereto, and then 5.28 g of sodium tert-butoxide (53.8 mmol)are added. The reaction mixture is heated to boiling under a protectiveatmosphere for 24 h. The mixture is subsequently partitioned betweentoluene and water, and the organic phase is washed three times withwater and dried over Na₂SO₄ and concentrated by rotary evaporation.After the crude product has been filtered through silica gel withtoluene, the remaining residue is recrystallized from heptane/tolueneand finally sublimed under high vacuum. The purity is 99.9% (HPLC). Theyield of compound (5-1) is 14 g (60% of theory).

Synthesis of Compounds (5-2) and (5-3)

In a manner analogous to the synthesis of compound (5-1) described inExample 1, the following compounds (5-2) and (5-3) are also prepared:

In an analogous manner, the following compounds are obtained:

Reactant 1 Reactant 2 Product Yield 5-2

50% 5-3

45%

B) Device Examples

OLEDs of the invention and OLEDs according to the prior art are producedby a general method according to WO 04/058911, which is adapted to thecircumstances described here (e.g. materials).

In the inventive examples which follow, the data for various OLEDs arepresented. Substrates used are glass plates coated with structured ITO(indium tin oxide) of thickness 50 nm. The OLEDs have the followinglayer structure: substrate/p-doped hole transport layer (HIL1)/holetransport layer (HTL)/p-doped hole transport layer (HTL2)/electronblocker layer (EBL)/emission layer (EML)/electron transport layer(ETL)/electron injection layer (EIL) and finally a cathode. The cathodeis formed by an aluminium layer of thickness 100 nm. The materialsrequired for production of the OLEDs are shown in Table 1.

All materials are applied by thermal vapour deposition in a vacuumchamber. In this case, the emission layer always consists of at leastone matrix material (host material) and an emitting dopant (emitter)which is added to the matrix material(s) in a particular proportion byvolume by co-evaporation. Details given in such a form as H1:SEB(5%)mean here that the material H1 is present in the layer in a proportionby volume of 95% and SEB in a proportion by volume of 5%. In ananalogous manner, the electron transport layers or the hole injectionlayers may also consist of a mixture of two or more materials.

The OLEDs are characterized in a standard manner. For this purpose, theexternal quantum efficiency (EQE, measured in percent) is determined asa function of luminance, calculated from current-voltage-luminancecharacteristics (IUL characteristics) assuming Lambertian radiationcharacteristics, and the lifetime. The parameter EQE @ 10 mA/cm² refersto the external quantum efficiency at a current density of 10 mA/cm².LD80 @ 60 mA/cm² is the lifetime before the OLED, given a startingbrightness at constant current of 60 mA/cm², has fallen to 80% of thestarting intensity.

TABLE 1 Structures of the materials used

F4TCNQ

HIM

H1

SEB

H2

TEG

ETM

LiQ

HTM1

HTM2

HTM3

HTMv1

HTMv2

Example 1

The inventive compound HTM1 and the comparative compound HTMv1 arecompared with one another in a blue-emitting OLED stack. The structureof the stack is as follows: HIM:F4TCNQ(5%)(20 nm)/HIM(155nm)/HTM1:F4TCNQ(5%)(20 nm)/HTM1(20 nm)/H1:SEB(5%)(20 nm)/ETM:LiQ(50%)(30nm)/LiQ(1 nm). In the comparative example, rather than HTM1, HTMv1 isused in all relevant layers.

The evaluation of the external quantum efficiencies at 10 mA/cm² for theexperiments conducted shows the following results: HTM1 achieves 7.7%EQE, whereas HTMv1 achieves only 7.0%. The lifetimes of the devicesproduced until a drop to 80% of the starting intensity at a constantcurrent of 60 mA/cm² show the advantage of compound HTM1 even moreclearly. These extend to 380 hours in the case of HTM1, whereas HTMv1achieves only 270 hours.

Example 2

The same two materials as in Example 1 are used to produce a tripletgreen component having the following structure: HIM:F4TCNQ(5%)(20nm)/HIM(210 nm)/HTM1:F4TCNQ(5%)(20 nm)/HTM1(20 nm)/H2:TEG(10%)(30nm)/ETM:LiQ(50%)(40 nm)/LiQ(1 nm). In the comparative example, HTM1 isreplaced by HTMv1.

The external quantum efficiencies show a similar trend to that in theblue-emitting OLED of Example 1. The external quantum efficiency forHTM1 at 2 mA/cm² in this experiment is 19.4%. The component comprisingHTMv1 achieves 19.1%. The lifetime of HTM1 here too is much higher thanfor the comparative HTM. HTM1 at 20 mA/cm² has a lifetime before a dropto 80% of the starting intensity of 160 hours. HTMv1 has an LT80 of 110hours.

Example 3

In a further experiment, the compounds HTM2 and HTMv2 are compared.Here, the different performance data are even more clearlydistinguishable. Again, the blue singlet stack (cf. Example 1) with thefollowing structure is used: HIM:F4TCNQ(5%)(20 nm)/HIM(155nm)/HTM2:F4TCNQ(5%)(20 nm)/HTM2(20 nm)/H1:SEB(5%)(20 nm)/ETM:LiQ(50%)(30nm)/LiQ(1 nm), with insertion of HTMv2 rather than HTM2 at allappropriate points in the stack in the comparative experiment.

In the evaluation of the experimental data, the experiment comprisingHTM2 shows an external quantum efficiency at 10 mA/cm² of 7.9%, whereasHTMv2 shows only 7.3%. The lifetimes show a clear difference between thetwo materials. The stack comprising HTM2 has a lifetime LT80 at 60mA/cm² of 330 hours. HTMv2 under the same conditions achieves only 190hours.

Example 4

Similar trends are seen as well in the triplet green component tested.The stack is analogous to the above-described green-emitting OLED stack(cf. example 3): HIM:F4TCNQ(5%)(20 nm)/HIM(210nm)/HTM2:F4TCNQ(5%)(20)/HTM2(20)/H2:TEG(10%)(30 nm)/ETM:LiQ(50%)(40nm)/LiQ(1 nm). In the comparative experiment, again, HTM2 is replaced byHTMv2.

The external quantum efficiency at 2 mA/cm² for HTM2 is 19.2%; HTMv2achieves only 17.7%. The LT80 @ 20 mA/cm² in the HTM2 stack is 170hours, and in the comparative structure comprising HTMv2 100 hours.

Example 5

Finally, the compound HTM3 is also tested in a singlet blue stack. Thishas the following structure: (HIM:F4TCNQ(5%)(20 nm)/HIM(155nm)/HTM3:F4TCNQ(5%)(20 nm)/HTM3 (20 nm)/H1:SEB(5%)(20 nm)/ETM:UQ(50%)(30nm)/LiQ(1 nm)). The compound HTM3 here exhibits an external quantumefficiency at 10 mA/cm² of 7.6%. The lifetime to 80% and 60 mA/cm² is340 hours.

Example 6

In a triplet green component having the following structure:HIM:F4TCNQ(5%)(20 nm)/HIM(210 nm)/HTM3:F4TCNQ(5%)(20 nm)/HTM3(20nm)/H2:TEG(10%)(30 nm)/ETM:LiQ(50%)(40 nm)/LiQ(1 nm), the compound HTM3shows an external quantum efficiency at 2 mA/cm² of 17.8% and a lifetimeLT80 @ 20 mA/cm² of 150 hours.

In summary, the device examples show that excellent performance data areachieved in OLEDs with the inventive compounds, especially excellentlifetime and quantum efficiency, both in systems comprising fluorescentemitters and in systems comprising phosphorescent emitters.

Substitution by an arylamino group in the specific position on thespirobifluorene as present in the compounds HTM1 to HTM3 additionallyleads to much improved device performance compared to substitution inthe 2 and 3 positions as exists in comparative examples HTMv1 and HTMv2.

The invention claimed is:
 1. A compound of the formula (I)

which has a group of the formula (T)

bonded at two adjacent positions marked by * to the base structure offormula (I), where the condensation is such that any bond marked by * informula (T) is attached at a position marked by * to the base structureof formula (I); which optionally substituted at one or more positionsshown as unsubstituted in the base structure of formula (I) and thegroup of the formula (T) by an R¹ radical; wherein the group —Ar¹-A canonly be bonded at one or more positions shown as unsubstituted in thebase structure of formula (I); and which has the following definitionsof the variables: A is the same or different at each instance and is agroup of the formula (A1), (A2) or (A3) which is bonded via the bondmarked with # and optionally substituted at one or more positions shownas unsubstituted by an R² radical;

Ar¹ is the same or different at each instance and is a single bond or anaromatic or heteroaromatic ring system which has 6 to 30 aromatic ringatoms and optionally substituted by one or more R² radicals; Ar² is thesame or different at each instance and is an aromatic or heteroaromaticring system which has 6 to 30 aromatic ring atoms and optionallysubstituted by one or more R² radicals; X is the same or different ateach instance and is a single bond or a group selected from BR², C(R²)₂,Si(R²)₂, C═O, O, S, S═O, SO₂, NR², PR² and P(═O)R²; Y is selected from Oand S; Z is selected from O, S, and a single bond, where Z is not asingle bond when Y is O; R⁰ is H; R¹ is the same or different at eachinstance and is selected from H, D, F, C(═O)R³, CN, Si(R³)₃, P(═O)(R³)₂,OR³, S(═O)R³, S(═O)₂R³, straight-chain alkyl or alkoxy groups having 1to 20 carbon atoms, branched or cyclic alkyl or alkoxy groups having 3to 20 carbon atoms, alkenyl or alkynyl groups having 2 to 20 carbonatoms, aromatic ring systems having 6 to 40 aromatic ring atoms, andheteroaromatic ring systems having 5 to 40 aromatic ring atoms; wheretwo or more R¹ radicals optionally joined to one another and optionallyform a ring; where the alkyl, alkoxy, alkenyl and alkynyl groupsmentioned and the aromatic ring systems and heteroaromatic ring systemsmentioned optionally each be substituted by one or more R³ radicals; andwhere one or more CH₂ groups in the alkyl, alkoxy, alkenyl and alkynylgroups mentioned optionally be replaced by —R³C═CR³—, —C≡C—, Si(R³)₂,C═O, C═NR³, —C(═O)O—, —C(═O)NR³—, NR³, P(═O)(R³), —O—, —S—, SO or SO₂;R² is the same or different at each instance and is selected from H, D,F, C(═O)R³, CN, Si(R³)₃, N(R³)₂, P(═O)(R³)₂, OR³, S(═O)R³, S(═O)₂R³,straight-chain alkyl or alkoxy groups having 1 to 20 carbon atoms,branched or cyclic alkyl or alkoxy groups having 3 to 20 carbon atoms,alkenyl or alkynyl groups having 2 to 20 carbon atoms, aromatic ringsystems having 6 to 40 aromatic ring atoms, and heteroaromatic ringsystems having 5 to 40 aromatic ring atoms; where two or more R²radicals optionally be joined to one another and optionally form a ring;where the alkyl, alkoxy, alkenyl and alkynyl groups mentioned and thearomatic ring systems and heteroaromatic ring systems mentionedoptionally each be substituted by one or more R³ radicals; and where oneor more CH₂ groups in the alkyl, alkoxy, alkenyl and alkynyl groupsmentioned optionally be replaced by —R³C═CR³—, —C≡C—, Si(R³)₂, C═O,C═NR³, —C(═O)O—, —C(═O)NR³—, NR³, P(═O)(R³), —O—, —S—, SO or SO₂; R³ isthe same or different at each instance and is selected from H, D, F,C(═O)R⁴, CN, Si(R⁴)₃, N(R⁴)₂, P(═O)(R⁴)₂, OR⁴, S(═O)R⁴, S(═O)₂R⁴,straight-chain alkyl or alkoxy groups having 1 to 20 carbon atoms,branched or cyclic alkyl or alkoxy groups having 3 to 20 carbon atoms,alkenyl or alkynyl groups having 2 to 20 carbon atoms, aromatic ringsystems having 6 to 40 aromatic ring atoms, and heteroaromatic ringsystems having 5 to 40 aromatic ring atoms; where two or more R¹ or R²radicals optionally be joined to one another and optionally form a ring;where the alkyl, alkoxy, alkenyl and alkynyl groups mentioned and thearomatic ring systems and heteroaromatic ring systems mentionedoptionally each be substituted by one or more R⁴ radicals; and where oneor more CH₂ groups in the alkyl, alkoxy, alkenyl and alkynyl groupsmentioned optionally be replaced by —R⁴C═CR⁴—, —C≡C—, Si(R⁴)₂, C═O,C═NR⁴, —C(═O)O—, —C(═O)NR⁴—, NR⁴, P(═O)(R⁴), —O—, —S—, SO or SO₂; R⁴ isthe same or different at each instance and is selected from H, D, F, CN,alkyl groups having 1 to 20 carbon atoms, aromatic ring systems having 6to 40 aromatic ring atoms and heteroaromatic ring systems having 5 to 40aromatic ring atoms; where two or more R⁴ radicals optionally be joinedto one another and optionally form a ring; and where the alkyl groups,aromatic ring systems and heteroaromatic ring systems mentionedoptionally be substituted by F or CN; q is the same or different at eachinstance and is 0 or 1, where at least one q in formula (A2) is 1; i, k,m, n and p are the same or different at each instance and are 0 or 1,where at least one of these indices is
 1. 2. The compound according toclaim 1, wherein it corresponds to one of the following formulae:

where the symbols that occur are as defined in claim 1, wherein thegroup —Ar¹-A can only be bonded at one or more positions shown asunsubstituted in the base structure of formulae (I-1) through (I-12);and the compounds optionally be substituted at positions shown asunsubstituted by R¹ radicals.
 3. The compound according to claim 1,wherein A is a group of the formula (A-1).
 4. The compound according toclaim 1, wherein Ar¹ is the same or different at each instance and isselected from a single bond and a divalent group derived from benzene,biphenyl, terphenyl, fluorene, spirobifluorene, indenofluorene,carbazole, dibenzofuran or dibenzothiophene, each optionally substitutedby R² radicals, or a combination of two or more of these groups, but notmore than 30 aromatic ring atoms optionally present in Ar¹.
 5. Thecompound according to claim 1, wherein Ar² is the same or different ateach instance and is selected from phenyl, biphenyl, terphenyl,fluorenyl, spirobifluorenyl, indenofluorenyl, naphthyl, phenanthrenyl,furanyl, benzofuranyl, dibenzofuranyl, thiophenyl, benzothiophenyl,dibenzothiophenyl, carbazolyl, indolocarbazolyl and indenocarbazolyl,each of which optionally substituted by one or more R² radicals.
 6. Thecompound according to claim 1, wherein X is a single bond.
 7. Thecompound according to claim 1, wherein R¹ and R² are the same ordifferent at each instance and are H, D, F, CN, a straight-chain alkylgroup having 1 to 10 carbon atoms or a branched or cyclic alkyl grouphaving 3 to 10 carbon atoms, or an aromatic or heteroaromatic ringsystem having 6 to 25 aromatic ring atoms, where said alkyl and alkoxygroups and said aromatic or heteroaromatic ring systems each optionallysubstituted by one or more R³ radicals.
 8. The compound according toclaim 1, wherein p is 1, and in that all the other indices k, i, m and nare 0, or wherein k is 1, and in that all the other indices m, n and pare
 0. 9. The compound according to claim 1, wherein the sum total ofthe indices i, k, m, n and p is
 1. 10. The compound according to claim1, wherein the Y group is S, and the Z group is O, S or a single bond.11. The compound according to claim 1, wherein the Y group is S, and theZ group is a single bond.
 12. A process for preparing a compoundaccording to claim 1, comprising either A) first preparing aspirobifluorene base skeleton substituted by a reactive group byreacting a dibenzothiophenyl derivative with a fluorenone derivativebearing the reactive group and, in a later step, via an organometalliccoupling reaction, a diarylamino or carbazole group or an aryl orheteroaryl group substituted by a diarylamino or carbazole group isintroduced at the position of the reactive group, or B) reacting adibenzothiophenyl derivative with a fluorenone bearing a diarylamino orcarbazole group or an aryl or heteroaryl group substituted by adiarylamino or carbazole group is involved, or C) first preparing aspirobifluorene base skeleton by reacting a dibenzothiophenyl derivativewith a fluorenone derivative, then the latter is functionalized with areactive group and, in a later step, via an organometallic couplingreaction, a diarylamino or carbazole group or an aryl or heteroarylgroup substituted by a diarylamino or carbazole group is introduced atthe position of the reactive group.
 13. An oligomer, polymer ordendrimer containing one or more compounds of the formula (I) accordingto claim 1, wherein the bond(s) to the polymer, oligomer or dendrimeroptionally localized at any desired positions substituted by R⁰, R¹ orR² in formula (I).
 14. A formulation comprising at least one compoundaccording to claim 1, or at least one polymer, oligomer or dendrimeraccording to claim 13, and at least one solvent.
 15. A method comprisingutilizing the compound according to claim 1, or the oligomer, polymer ordendrimer according to claim 13, in an electronic device.
 16. Anelectronic device comprising at least one compound according to claim 1or at least one oligomer, polymer or dendrimer according to claim 13.17. The electronic device according to claim 16, selected from the groupconsisting of organic integrated circuits (OICs), organic field-effecttransistors (OFETs), organic thin-film transistors (OTFTs), organiclight-emitting transistors (OLETs), organic solar cells (OSCs), organicoptical detectors, organic photoreceptors, organic field-quench devices(OFQDs), organic light-emitting electrochemical cells (OLECs), organiclaser diodes (O-lasers) and organic electroluminescent devices (OLEDs).18. The electronic device according to claim 17, wherein the at leastone compound or the at least one oligomer, polymer or dendrimer ispresent in a layer selected from hole transport layers and emittinglayers.
 19. The electronic device according to claim 18, wherein the atleast one compound or the at least one oligomer, polymer or dendrimer ispresent in an emitting layer together with one or more phosphorescentemitters.
 20. The electronic device according to claim 18, wherein theat least one compound or the at least one oligomer, polymer or dendrimeris present in a hole transport layer together with one or morep-dopants.
 21. The compound according to claim 1, wherein it correspondsto one of the following formulae: